U.S. patent number 10,904,403 [Application Number 16/511,325] was granted by the patent office on 2021-01-26 for methods, systems, and scanners for scanning bound documents with varying light intensity.
This patent grant is currently assigned to Xerox Corporation. The grantee listed for this patent is XEROX CORPORATION. Invention is credited to Ramanathan Arunachalam, Shankar Durai, Anandha Kumar, Saranraj Velayutham.
![](/patent/grant/10904403/US10904403-20210126-D00000.png)
![](/patent/grant/10904403/US10904403-20210126-D00001.png)
![](/patent/grant/10904403/US10904403-20210126-D00002.png)
![](/patent/grant/10904403/US10904403-20210126-D00003.png)
![](/patent/grant/10904403/US10904403-20210126-D00004.png)
![](/patent/grant/10904403/US10904403-20210126-D00005.png)
![](/patent/grant/10904403/US10904403-20210126-D00006.png)
![](/patent/grant/10904403/US10904403-20210126-D00007.png)
![](/patent/grant/10904403/US10904403-20210126-D00008.png)
![](/patent/grant/10904403/US10904403-20210126-D00009.png)
![](/patent/grant/10904403/US10904403-20210126-D00010.png)
View All Diagrams
United States Patent |
10,904,403 |
Durai , et al. |
January 26, 2021 |
Methods, systems, and scanners for scanning bound documents with
varying light intensity
Abstract
The present disclosure discloses methods, systems and scanners
for scanning document with varying light intensity. The method
includes receiving a bound document positioned on an upper surface
of a platen, for scanning, wherein the bound document, when opened
for scanning, includes a flat region and a curved region. A
distance between the bound document positioned on the platen and a
contact image sensor (CIS) is continuously monitored and measured,
to detect the curved region. Upon detection, a control command is
generated to vary the intensity of the light to be emitted from a
light source. Then, light with varying intensity is emitted for
illuminating the curved region of the bound document. Thereafter,
the light reflected from the bound document is received for
capturing an image of the bound document. Finally, a digital
version of the bound document is generated without any dark strip
or without any distortion.
Inventors: |
Durai; Shankar (Vellore
District, IN), Velayutham; Saranraj (Thanjavur,
IN), Arunachalam; Ramanathan (Chennai, IN),
Kumar; Anandha (Thuraiyur, IN) |
Applicant: |
Name |
City |
State |
Country |
Type |
XEROX CORPORATION |
Norwalk |
CT |
US |
|
|
Assignee: |
Xerox Corporation (Norwalk,
CT)
|
Appl.
No.: |
16/511,325 |
Filed: |
July 15, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04N
1/32464 (20130101); G06T 5/002 (20130101); H04N
1/4092 (20130101); H04N 1/00748 (20130101); G06T
7/12 (20170101); G06T 2207/30176 (20130101) |
Current International
Class: |
H04N
1/04 (20060101); G06T 7/12 (20170101); H04N
1/00 (20060101); H04N 1/409 (20060101); G06T
5/00 (20060101); H04N 1/32 (20060101) |
Field of
Search: |
;358/475,509,497,474
;355/67-70 ;250/205,216 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Lee; Cheukfan
Claims
What is claimed is:
1. A scanner for scanning a bound document, the scanner comprising:
a platen having an upper surface and a lower surface, wherein on
the upper surface of the platen, a bound document is positioned for
scanning, and wherein the bound document, when opened for scanning,
comprises a flat region and a curved region; a scan head disposed
beneath and in proximity of the lower surface of the platen, the
scan head is to move across, and in proximity to, to the lower
surface of the platen so as to scan the bound document placed on
the upper surface of the platen, wherein the scan head comprises: a
light source to emit light for illuminating the bound document,
wherein the light source comprises outer arrays of light emitting
devices and inner arrays of light emitting devices; a contact image
sensor (CIS) to receive the light reflected from the bound document
for capturing an image of the bound document; at least one distance
sensor to continuously monitor and measure a distance between the
bound document and the CIS to detect the curved region of the bound
document; and a controlling processor, coupled to the at least one
distance sensor, to generate a control command to vary the
intensity of the light to be emitted from the light source, upon
detection of the curved region of the bound document in order to
capture a complete image of the bound document at the curved
region, wherein the controlling processor activates the outer
arrays of light emitting devices during the entire scanning
operation, wherein the controlling processor activates the inner
arrays of light emitting devices, upon detection of the curved
region of the bound document, and wherein the controlling processor
deactivates the inner arrays of light emitting devices when an end
of the curved region is detected; and an image processor to
generate a digital version of the bound document without any dark
strip or without any distortion.
2. The scanner of claim 1, wherein the bound document is positioned
on the platen in a particular direction.
3. The scanner of claim 1, wherein the controlling processor
increases the illumination intensity when the distance between the
bound document and the CIS starts increasing in the curved region,
and then gradually decreases the illumination intensity at the end
of the curved region.
4. The scanner of claim 1, wherein the image processor receives the
captured image of the bound document from the CIS to create the
digital version of the bound document.
5. The scanner of claim 1, wherein the light source emits light
with a predefined intensity when the measured distance is within a
specified range and emits light with an increased intensity in the
bound document's curved region where the measured distance is above
the specified range.
6. The scanner of claim 1, wherein the controlling processor varies
the intensity of light such that content present in the curved
region of the bound document is captured, upon detection of the
curved region.
7. The scanner of claim 1, wherein the light source comprises light
emitting devices whose output intensity is adapted to be varied
with the use of additional light emitting devices.
8. The scanner of claim 1, wherein the outer arrays comprise a
plurality of light emitting diodes and the inner arrays comprise a
plurality of light emitting diodes.
9. The scanner of claim 1, wherein the controlling processor
activates individual light emitting devices of the inner
arrays.
10. The scanner of claim 1, wherein the outer arrays of light
emitting devices and the inner arrays of light emitting devices are
arranged on both sides of the CIS.
11. A method for scanning a bound document, the method comprising:
receiving a bound document positioned on an upper surface of a
platen for scanning, wherein the bound document, when opened for
scanning, comprises a flat region and a curved region; continuously
monitoring and measuring a distance between the bound document
positioned on the platen and a contact image sensor (CIS), to
detect the curved region of the bound document; upon detection,
generating a control command to vary the intensity of the light to
be emitted from a light source, wherein the light source comprises
outer arrays of light emitting devices and inner arrays of light
emitting devices; emitting light with varying intensity for
illuminating the curved region of the bound document, wherein
emitting light with varying intensity comprises: activating the
outer arrays of light emitting devices during the entire scanning
operation; activating the inner arrays of light emitting devices,
upon detection of the curved region of the bound document; and
deactivating the inner arrays of light emitting devices when an end
of the curved region is detected; receiving the light reflected
from the bound document for capturing an image of the bound
document; and generating a digital version of the bound
document.
12. The method of claim 11, further comprising emitting light with
a predefined intensity when the measured distance is within a
specified range and emitting light with an increased intensity in
the bound document's curved region where the measured distance is
above the specified range.
13. The method of claim 11, further comprising generating the
control command to vary the intensity of light such that content
present in the curved region of the bound document is captured,
upon detection of the curved region.
14. The method of claim 11, wherein the light source includes a
plurality of light emitting devices whose output intensity is
adapted to be varied with the use of additional light emitting
devices.
15. The method of claim 11, wherein the outer arrays comprise a
plurality of light emitting diodes and the inner arrays comprise a
plurality of light emitting diodes.
16. The method of claim 11, further comprising activating one or
more groups of light emitting devices of the inner arrays.
17. The method of claim 11, further comprising activating
individual light emitting devices of the inner arrays.
18. The method of claim 11, wherein emitting light with varying
intensity comprising: emitting the light with increased
illumination intensity when the distance between the bound document
and the CIS unit starts increasing in the curved region; and
gradually decreasing the illumination intensity of the emitted
light at the end of the curved region.
19. A method, comprising: receiving a bound document on a platen of
a scanner for scanning, the bound document comprising a flat region
and a curved region, wherein the scanner comprises a light source
having outer arrays of light emitting devices and inner arrays of
light emitting devices; initiating scanning of the bound document;
activating the outer arrays to emit light from the light source to
illuminate the bound document, the outer arrays are activated
during the entire scanning operation; while scanning, continuously
monitoring and measuring distance between the bound document and a
contact image sensor, to detect the curved region; upon detection
of the curved region, generating a control command to increase the
intensity of the light source at or along the curved region; in
addition to the activated outer arrays, activating the inner arrays
to increase the intensity of the light source to be emitted in the
curved region of the bound document, wherein the inner arrays are
activated only when the curved region is detected; deactivating the
inner arrays of light emitting devices when an end of the curved
region is detected; receiving light reflected from the bound
document to capture a complete image of the bound document; and
generating a digital version of the bound document.
20. The method of claim 19, further comprising activating one or
more groups of light emitting device of the inner arrays.
21. The method of claim 19, further comprising activating
individual light emitting devices of the inner arrays.
22. A light source for scanning a bound document, wherein the bound
document having a flat region and a curved region, comprising:
outer arrays having a plurality of light emitting devices, wherein
the outer arrays are activated during the entire scanning operation
of a bound document; and inner arrays having a plurality of light
emitting devices, wherein the inner arrays are activated only
during scanning of the curved region of the bound document, wherein
the inner arrays are activated to increase intensity of light in
the curved region of the bound document in order to increase the
reach through the curved region of the bound document, and wherein
the inner arrays are deactivated when an end of the curved region
is detected.
Description
TECHNICAL FIELD
The present disclosure relates generally to the field of scanning
devices. In particular, the present disclosure relates to methods,
systems and scanning devices for scanning bound documents with
varying light intensity.
BACKGROUND
Many institutions, such as the Library of Congress, universities,
bookstores, and private enterprises have vast collections of bound
documents. Bound documents include not only books, but also
periodicals, manuscripts, pamphlets, brochures, newspapers,
manuals, and any other document having a bound edge. With the
advent of improved imaging, storage, and distribution techniques,
bound documents are nowadays converted into digital form to reduce
the cost of storage, facilitate remote access, enable simultaneous
access to multiple users, facilitate search and retrieval of
information, and/or protect information in rare or out-of-print
works from loss or destruction. The bound documents are converted
into digital form with the help of a photocopier device or a
document scanner. The scanning of the bound documents such as books
always creates a black strip at the center of the copy because of
the curvature of the book in the center region. Several scanners
are available in the market for scanning bound documents or other
documents. One such example is a flat-bed platen scanner.
The traditional flat-bed platen scanner 100 scans bound documents
such as a book 112 in a face-down position as shown in FIG. 1. When
the book 112 is in face-down position, a scan head 104 disposed
beneath and in the proximity of a lower surface of the platen
102-L. The scan head 104 moves across, and in proximity to, the
lower surface of the platen 102-L to scan the book 112 placed on an
upper surface of the platen 102-U. The scan head 104 typically
includes a light source 106 to illuminate the book 112 and, a
contact image sensor (CIS) 108 to receive light reflected from the
book 112 during the scanning process. The contact image sensor 108
is precisely calibrated to detect light reflected from the book
surface at a particular intensity. However, during book 112
scanning as the sensor 108 travels along the entire length of the
book 112, some of the light is not reflected back to the sensor
108, at the center region of the book 112. Because of the curvature
of the book surface, some of the light misses the image sensor 108
and because of the increase in distance of book surface from the
sensor, the intensity (shown through lines marked 101) of the light
reaching the image sensors 108 is less as shown in FIG. 1. This
ultimately leads to darker image reproduction (or black strip at
the center region) as well as distortion. Such an effect is
illustrated in FIG. 2, marked as 117. The effect occurs due to the
distance of the center region of the book 112 from the platen 102
as illumination required for such distance is outside a defined
specification of the light source disposed for illumination of the
book 112.
To avoid this, the user sometimes has to push the book hard on to
the platen to decrease the gap between the book surface and the
sensor. The application of user's force to the centre region of the
book may help but such force sometimes can damage the center region
of the book or even the entire book.
Therefore, there is a need for improved devices, systems and
methods to be able to scan or copy bound documents without dark
image reproduction, without distortion and/or to overcome above
mentioned concerns.
SUMMARY
According to aspects illustrated here, a scanner for scanning a
bound document is disclosed. The scanner includes a platen having
an upper surface and a lower surface, wherein on the upper surface
of the platen, a bound document is positioned for scanning, and
wherein the bound document, when opened for scanning, includes a
flat region and a curved region. The scanner includes a scan head
disposed beneath and in proximity of the lower surface of the
platen, the scan head moves across, and in proximity to, to the
lower surface of the platen so as to scan the bound document placed
on the upper surface of the plate. The scan head includes a light
source to emit light for illuminating the bound document; a contact
image sensor (CIS) to receive the light reflected from the bound
document for capturing an image of the bound document, and wherein
the scan head further includes at least one distance sensor to
continuously monitor and measure a distance between the bound
document and the CIS to detect the curved region of the bound
document; and a controlling processor, coupled to the at least one
distance sensor, to generate a control command to vary the
intensity of the light to be emitted from the light source, upon
detection of the curved region of the bound document in order to
capture a complete image of the bound document at the curved
region. The scan head further includes an image processor for
generating a digital version of the bound document without any dark
strip or without any distortion.
A method for scanning a bound document is disclosed. The method
includes: receiving a bound document positioned on an upper surface
of a platen, for scanning, wherein the bound document, when opened
for scanning, includes a flat region and a curved region;
continuously monitoring and measuring a distance between the bound
document positioned on the platen and a contact image sensor (CIS),
to detect the curved region of the bound document; upon detection,
generating a control command to vary the intensity of the light to
be emitted from a light source, upon detection of the curved region
of the bound document; emitting light with varying intensity for
illuminating the curved region of the bound document; receiving the
light reflected from the bound document for capturing an image of
the bound document; and generating a digital version of the bound
document.
According to further aspects, a method for scanning a bound
document is disclosed. The method includes: receiving a bound
document on a platen of a scanner for scanning, the bound document
includes a flat region and a curved region, wherein the scanner
includes a light source having outer arrays of light emitting
devices and inner arrays of light emitting devices; initiate
scanning of the bound document; activating the outer arrays to emit
light from the light source to illuminate the bound document, the
outer arrays are activated during the entire scanning operation;
while scanning, continuously monitoring and measuring distance
between the bound document and a contact image sensor, to detect
the curved region; upon detection of the curved region, generating
a control command to increase the intensity of the light source at
or along the curved region; in addition to the activated outer
arrays, activating the inner arrays of the light source to increase
the intensity of light in the curved region of the bound document,
the inner arrays are activated only when the curved region is
detected; receiving light reflected from the bound document to
capture a complete image of the bound document; and generating a
digital version of the bound document.
According to additional aspects, a light source is disclosed. The
light source includes outer arrays having a plurality of light
emitting devices, wherein the outer arrays are activated during the
entire scanning operation of a bound document, wherein the bound
document having a flat region and a curved region; and inner arrays
having a plurality of light emitting devices, wherein the inner
arrays are activated only during scanning of the curved region of
the bound document, wherein the inner arrays are activated to
increase intensity of light in the curved region of the bound
document in order to increase the reach through the curved region
of the bound document.
Other and further aspects and features of the disclosure will be
evident from reading the following detailed description of the
embodiments, which are intended to illustrate, not limit, the
present disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
The illustrated embodiments of the subject matter will be best
understood by reference to the drawings, wherein like parts are
designated by like numerals throughout. The following description
is intended only by way of example, and simply illustrates certain
selected embodiments of devices, systems, and processes that are
consistent with the subject matter as claimed herein:
FIG. 1 shows a known scanning process in operation, while
FIG. 2 illustrates a dark image reproduction, resulted due to the
known scanning process as shown in FIG. 1;
FIG. 3 shows a physical scanner in context of the present
disclosure, while
FIG. 4 shows a bound document placed on a platen of the
scanner;
FIG. 5 shows the scanner in operation;
FIG. 6 illustrates a top view of the scanner in operation, in
accordance with an embodiment of the present disclosure;
FIG. 7 illustrates a top view of a scan head of the scanner, in
accordance with an embodiment of the present disclosure;
FIG. 8 illustrates a block diagram of the scanner, in accordance
with an embodiment of the present disclosure;
FIG. 9 shows a light source having a plurality of light emitting
devices in form of outer arrays and inner arrays;
FIG. 10 shows a front view of the scanner in operation, while FIG.
11 represents a view of the scanner along A-A axis;
FIG. 12 is a method flowchart for scanning a bound document;
and
FIG. 13 is a method flowchart for scanning or copying a bound
document.
DESCRIPTION
A few inventive aspects of the disclosed embodiments are explained
in detail below with reference to the various figures. Embodiments
are described to illustrate the disclosed subject matter, not to
limit its scope, which is defined by the claims. Those of ordinary
skill in the art will recognize a number of equivalent variations
of the various features provided in the description that
follows.
Non-Limiting Definitions
In various embodiments of the present disclosure, definitions of
one or more terms that will be used in the document are provided
below. For a person skilled in the art, it is understood that the
definitions are provided just for the sake of clarity and are
intended to include more examples than just provided below.
The "scanner" refers to a single or a combination of multiple
devices to perform one or more functions, but not limited to,
scanning, printing, copying, imaging, and so forth. The scanner
includes software, hardware, firmware, or combination thereof. The
scanner creates a digital document corresponding to a paper
document (i.e., a printed form). In context of the present
disclosure, the scanner scans a document such as a bound document
and creates a digital version of the bound document without any
dark image reproduction in a center region of the bound document
and/or without any distortion. To this end, the scanner includes
one or more components such as distance sensors, one or more light
sources, and a controlling processor. The scanner additional
includes a platen, a scan head, a contact image sensor, an image
processor and other components for implementing the present
disclosure and the same will be discussed below in greater
detail.
The term "document" refers to a paper document, which can be in a
physical form, such as printed on paper including information in
form of text, graphics and/or image. The document can be any bound
document such as a bound book. Other examples include periodicals,
manuscripts, pamphlets, brochures, newspapers, manuals, and any
other document having curvature in a center region of the bound
document. The bound document has a flat region and a curved region
typically in the center of the bound document. The curved region
can also be referred to as a center region. The term "digital
document" refers to a document in a virtual or software form
(embodied in a software file) of the physical form. The digital
document is generated by the scanner. The scanner receives the
bound document as an input and generates the digital document
corresponding to the bound document as the output. In other words,
the scanner generates the digital version of the bound
document.
The term "light sources" refer to sources of light whose intensity
can be varied based on a signal received from the controlling
processor. The light sources can include any light emitting devices
such as light emitting diodes without limiting the scope of the
disclosure.
The term "image sensor" refers to a contact image sensors (CIS)
which is typically used in flat-bed platen scanners and is almost
in direct contact with the bound document to be scanned. The CIS
typically includes a linear array of detectors, covered by focusing
lenses.
The term "distance sensor" refers to a proximity sensor. The
proximity sensor is a sensor able to detect the presence of nearby
objects such as bound books, without any physical contact. The
proximity sensor often emits an electromagnetic field or a beam of
electromagnetic radiation (infrared, for instance), and looks for
changes in the field or return signal. Examples of proximity sensor
include but not limited to an inductive proximity sensor, a
capacitive proximity sensor, and a photoelectric sensor.
The term "controlling processor" refers to a processor that
controls or adjusts intensity of the light sources based on a
signal from the distance sensor. The controlling processor receives
a signal from the distance sensor, processes the signal, and sends
appropriate signals to the light sources for varying (includes
increasing and/or decreasing) illumination intensity. For example,
the controlling processor increases the illumination intensity upon
detection of the curved region. The controlling processor decreases
the illumination intensity when an end of the curved region is
detected. The controlling processor may be implemented as a
combination of hardware and programming (for example, programmable
instructions) to implement one or more functionalities.
Existing Scanner Solutions
FIG. 1 shows a schematic side view of an existing scanner 100 in
operation according to known solutions in the art.
Typically, the scanner 100 includes a housing (although not shown)
which supports a flat transparent platen 102. The platen 102 is
defined by an upper surface 102-U and a lower surface 102-L. The
scanner 100 further includes a scan head 104 which moves in X-axis
direction across the lower surface 102-L of the platen 102 to
perform the scanning process. The scan head 104 is guided by a scan
head track (not shown in figures) and is moved along the track by a
motive element (not shown, but typically includes a drive belt or
cable which pulls the scan head 104 in the x-axis direction). The
scan head 104 includes light sources 106 and a reflected light
receptor, i.e., a contact image sensor (CIS) 108. The CIS 108 is
coupled to an image processor 110 which is programmed to receive
the images from the CIS 108 and to create a copy of the original
bound document (i.e., in a digital form).
In operation, the scanner 100 scans a bound document such as a book
112. The book 112 has a flat region and a center region having a
curvature/curve in the center region. The curvature or the curve
"C" can be clearly seen in FIG. 1. For simplicity, page 1 marked as
"P1" and page 2 "P2" of the book 112 are shown. While scanning, the
book 112 is placed on the upper surface 102-U of the platen 102.
The bound book 112 is placed on the platen 102 so as to present
pages "P1" and "P2" to the scan head 104 as the scan head 104 moves
in X-axis direction across the lower surface 102-L of the platen
102. The bound book 112 includes a cover "CO", which defines a
curve "C" (i.e., curved region) of the bound book 112, where the
pages of the bound book 112 are joined to the cover "CO". As can be
seen in FIG. 1, the curve "C" of the bound book 112 forces the
pages "P1" and "P2" and to curve upwards, away from the upper
surface 102-U of the platen 102 in the curved region "C." As
further can be seen in FIG. 1, the portion of the pages "P1" and
"P2" of the bound book 112 in the curved region "C" is not oriented
in a parallel arrangement to the upper surface 102-U of the platen
102. Accordingly, light reflected from the portion of the pages
"P1" and "P2" in the curved region "C" is likely not be reflected
to the CIS 108, resulting in loss of scanned image/data from the
curved region "C." Further, since the portion of the pages "P1" and
"P2" in the curved region "C" is moved away from the platen 102,
the illumination of the pages by the light sources 106 in the
curved region "C" may not be sufficient to allow a decent image to
be captured. And the problem is particularly acute for very thick
bound documents, and more so when the text on the pages "P1" and
"P2" to be imaged intrudes deep into the curved region "C." Even
for relatively thin bound documents, if the cover "CO" and curved
region "C" are quite rigid, then text or images in the curved
region "C" are not imaged completely or may be poorly imaged.
Scanned images of bound documents often have distortions generated
by the scanning process. Depending on the bound book 112
orientation relative to the scanning direction when it lays on the
platen 102 and the elevation of the bound book 112 curved region
"C" above the platen 102, the distortion appears. As shown in FIG.
2, when the bound book 112 curved region is above the platen 102, a
scanned image of the bound book 112 usually includes a dark region
marked as 117 and has shadows ("shadow distortion") appearing in
the scanned image close to the curved region.
One approach to solve this problem is the application of user's
force to the curved region "C" of the bound document 112 to ensure
that the curved region "C" come within the light source's
illumination range. But such force can damage the curved region "C"
of the bound document 112 or even the entire bound document 112.
This is obviously undesirable since it will result in permanent
damage to the bound document 112.
To overcome the above mentioned problems, the present disclosure is
presented. The present disclosure discloses methods and systems for
scanning bound documents such that the output scanned document has
no dark region and is without distortion. To this end, the system
includes a distance sensor, light sources and a controlling
processor. The light sources include light sources whose intensity
can be adjusted by a command from the controlling processor. The
system further includes a platen, a contact image sensor, and an
image processor. The entire setup is placed on a supporting
platform below the platen and can be moved along the entire length
of the bound document. The system addresses the above mentioned
problems by using the distance sensor to measure the distance of
the bound document from the image sensor and accordingly adjusts
the intensity of the light from the light sources. When a user
places the bound document on the platen for copying, the distance
sensor measures the distance between the bound document's face and
the contact image sensor and based on the distance, intensity of
the light source is controlled. The contact image sensor starts
gathering image input from the reflected light and sends it to an
image processor. As the supporting platform is moved along length
of the bound document, the contact image sensor covers the whole
area of the bound document. When the distance between the bound
document's surface and the contact image sensor increases because
of the curvature of the paper in the bound document, the distance
sensor detects the increased distance and the controlling processor
increases the intensity of the light from the light sources. This
increase in intensity precisely offsets the loss of reflected light
by the bound document curvature. As a result, the image sensor
receives enough light reflected by the bound document's surface to
create a detailed copy of the bound document without a dark black
strip at the center region or without any distortion.
Exemplary Physical Scanner and its Working
FIG. 3 illustrates an exemplary physical scanner 300 according to
context of the disclosure, and the scanner 300 in operation is
shown in FIG. 5. The scanner 300 is presented with some hardware
and software enhancements to create a digital copy of a bound
document with image quality enhancements. Such scanner 300 will
further be described with reference to other figures. In place of
the scanner 300, the present disclosure may include a
multi-function device, a multi-function peripheral device, a
photocopier or the like. Although, the scanner 300 shown in FIG. 3
is a standalone device, but the scanner 300 can be a part of any
network as known or later developed network. As an example, the
scanner 300 may be connected to computing devices, mobile devices,
servers, or other devices via suitable networks. The scanner 300
may include functionalities of scanning, copying, imaging, etc. The
scanner 300 receives an input in the form of a bound document (a
printed version) such as a book 412 shown in FIG. 4. Various other
examples of the bound document 412 include periodicals,
manuscripts, pamphlets, brochures, newspapers, manuals, and any
other document having curved regions. These are few examples; the
disclosure can be implemented for any bound documents having a
curved region.
As shown in FIG. 4, a bound document 412 is placed on a platen of
the scanner 300. The bound document 412 includes a cover "CO," a
flat region and a curved region "C." As clearly seen, when the
distance between the bound document 412 and a scanning platform of
the scanner 300 (i.e., a contact image sensor, although not
visible) remains the same/constant, the region is defined as the
flat region (marked as region 1). As move forward, the distance
between the bound document 412 and the contact image sensor
(although not visible) starts increasing, the region is defined as
the curved region "C" (marked as region 2) and further where the
distance starts decreasing, the region is defined as end of the
curved region "C" (marked as region 3). After decreasing, the
distance between the bound document 412 and the contact image
sensor again remains constant, the region is again defined as flat
region (marked as region 4).
Upon receiving the bound document 412, the scanner 300 scans the
document 412 and generates a digital version of the bound document
412 as an output. In context of the current disclosure, the scanner
300 generates the digital version of the bound document 412 without
any dark image reproduction in the curved region "C" of the bound
document 412 and without any distortion. More structural and
functional details of the scanner 300 are shown and discussed in
conjunction with FIG. 5.
The proposed arrangement and internal working of the scanner 300 is
shown in FIG. 5 (marked as 500) as an exemplary implementation. As
shown, the scanner 300 includes a platen 502 (an upper surface
502-U and a lower surface 502-L), a scan head 504 having a contact
image sensor (CIS) 508, and an image processor 510. In context of
the current disclosure, the scanner 300 includes a distance sensor
sender 514-S and receiver 514-R (collectively distance sensor 514),
one or more light sources 506 and a controlling processor 516. The
arrangement of the scanner 300 is introduced such that the CIS 508
captures enough light near or along the curved region "C" in order
to capture an image of the bound document 412 without any dark
image reproduction in the curved region "C." The scanner 300
additional includes a user interface 301 as depicted in FIG. 3.
Through the user interface 301, a user can provide various inputs
related to scanning/copying such as number of copies, brightness,
etc. Through the user interface 301, several notification messages
can be displayed such as "scanning completed successfully" and so
on.
A user submits a bound document 412 (512 of FIG. 5) for scanning.
The user places the bound document 412 on the upper surface of the
platen 502-U. In operation, the scanner 300 receives the bound
document 412 for scanning and initiates scanning of the bound
document 412. While scanning, the distance sensor 514 continuously
measures the distance between the bound document 412 and the CIS
508 to detect a curved region "C" of the bound document 412. The
distance measurement is used to adjust or control the light
intensity so that when the bound document 412 is further from the
CIS 508 (such as near the curved region of the bound document 412)
the increase in light intensity prevents the creation of a dark
band/strip in the scanned image of the bound document 412.
Upon detection, the controlling processor 516 varies the intensity
of light at/along/near the curved region "C" of the bound document
412. For instance, if the distance between the bound document 412
and the CIS 508 is constant from the beginning, the light intensity
remains the same. If the distance between the bound document 412
and the CIS 508 starts varying, the controlling processor 516 sends
command signals to the light sources 506 for varying their
illumination intensity. In an implementation, the controlling
processor 516 is programmed to increase the illumination intensity
when the distance between the bound document 412 and the CIS 508
starts increasing in the curved region "C" of the bound document
412, and then gradually decrease the illumination intensity at the
end of curved region "C." As an example, the increase in intensity
of light at or along the curved region of the bound document 412,
can be shown through thick lines 517 of FIG. 5.
The controlling processor 516 increases the intensity of light such
that enough light reaches the curved region "C" of the bound
document 412 that is the reflected by the bound document 412. The
light reflected by the bound document 412 is captured by the CIS
508. Based on the captured light, the CIS 508 gathers an input
image of the bound document 412 and sends to the image processor
510 for further processing.
The image processor 510 finally generates a digital bound document
without any dark strip at the curved region "C" and/or without any
distortion. While generating the digital version, the image
processor 510 may increase the brightness and contrast of the
captured image at the location of the curved region "C" digitally.
So ultimately a clearer bright image is produced. Thus, by having
such arrangement of the scanner 300, the digital version of the
bound document 412 is produced without having any dark image
reproduction in the curved region "C" of the bound document
412.
FIG. 6 illustrates a top view 600 of the scanner 300 scanning an
open bound document 412, in accordance with an embodiment of the
present disclosure. The top view 600 shows the platen 502, the scan
head 504, the CIS 508 and the image processor 510. The view 600
further shows one or more distance sensors as 514a, 514b, 514c
(collectively 514) and so on. The arrangement of the scanner 300 is
introduced such that the CIS 508 captures enough light near or at
the curved region in order to capture an image of the bound
document without any dark image reproduction in the curved region
"C." The CIS 508 along with other components is shown in subsequent
FIG. 7. FIG. 7 illustrates a top view 700 of the scan head 504 of
the scanner 300, in accordance with an embodiment of the present
disclosure. In FIG. 7, light sources 506 is shown. The light
sources 506 include arrays of light emitting diodes such as 506-1
and 506-2, arranged on both sides of the CIS 508. More details on
the light source 506 will be discussed below.
FIG. 8 shows a block diagram 800 of the scanner 300 for
implementing the present disclosure. The scanner 300 for example,
is a flatbed scanner without limiting the scope of disclosure.
Reference to other figures may be made while discussing FIG. 8.
The scanner 300 includes a platen 502, a scan head 504, a contact
image sensor (CIS) 508, an image processor 510 and a memory 802.
The scanner 300 additionally may include a user interface. In
context of the current disclosure, the scanner 300 further includes
one or more distance sensors 514, a light source 506, and a
controlling processor 516. Each of the components coordinate and
communicate with each other for scanning a bound document such as
412. The scanner 300 scans a bound document and generates a digital
form of the bound document without any dark strip or without
distortion. The bound document 412 has a flat region along its edge
area and a curved region along its binging area. The bound book 412
can be any bound document having a curved region, without limiting
the scope of the disclosure.
The platen 502 has an upper surface and a lower surface. The scan
head 504 includes the light source 506, the CIS 508, the distance
sensor 514 and the controlling processor 516. The scan head 504 is
disposed beneath and in proximity of the lower surface of the
platen 502, the scan head 504 moves across, and in proximity to, to
the lower surface of the platen 502 so as to scan the bound
document 412 placed on the upper surface of the platen 502. The CIS
508 is placed close to the light source 506 and the distance sensor
514 is placed before the CIS 508 in a direction of forwarding
movement of the scan head 504. In one example, the length of the
scan head 504 is equal to the width of the platen 502. The light
source 506 is arranged on both sides of the CIS 508. The entire
setup is placed on a supporting platform below the platen 502 and
can be moved along the entire length of the bound document 412. All
components 504, 506, 508, 510, 514 and 516 are disposed below the
platen 502 in a movable configuration so as to allow the CIS 508 to
capture entire lower surface of the bound document 412. Although
FIG. 8 discusses a single distance sensor 514, but it is understood
that the present disclosure can include multiple distance sensors
(refer to FIG. 6) positioned at some distance from each other,
without limiting the scope of the disclosure.
In context of the present disclosure, the light source 506 includes
light emitting devices such as light emitting diodes whose
intensity can be adjusted or varied by a command from the
controlling processor 516. Light emitting diodes is one example,
but other examples of the light emitting devices can be considered.
For example, the intensity of the light source 506 can be varied
with the use of additional light emitting diodes. The light source
506 emits light with a predefined intensity when the measured
distance is within a specified range and emit lights with an
increased intensity in the bound document's curved region where the
measured distance is above the specified range. The range can be
pre-defined with the scanner 300 or can vary based on the type of
bound document. The light emitting diodes are arranged in the form
of arrays on both sides of the CIS 508. Some of the light emitting
diodes of the light source 506 are constantly activated to emit
light during the entire scanning operation. But to increase the
intensity of the light source 506, the controlling processor 516
activates (switched on) additional light emitting diodes of the
light source 506 to emit light to illuminate the curved region "C"
of the bound document 412. With the help of additional activated
light emitting diodes along with the already activated light
emitting diodes, the intensity of the light source 506 is
increased. At the end of the curved region "C," the activated light
emitting diodes are deactivated (switched off).
In an implementation, the light source 506 includes outer arrays of
light emitting diodes 507 and inner arrays of light emitting diodes
509. The outer and inner arrays should not be confused with their
positioning of the arrays and can be considered as primary and
secondary (auxiliary) arrays of light emitting diodes,
respectively. The light emitting diodes of the outer arrays 507 can
be called as outer light emitting diodes and the light emitting
diodes of the inner arrays 509 can be called as inner light
emitting diodes. The outer arrays 507 include multiple light
emitting diodes arranged on both sides of the CIS 508. The inner
arrays 509 include multiple light emitting diodes arranged on both
sides of the CIS 508. The outer arrays 507 are activated during the
entire scanning operation, i.e., entire scanning of the book. While
the inner arrays 509 are activated only near or along the curved
region of the bound book. The inner arrays 509 are activated in
addition to the activated outer arrays 507. Specifically, the inner
arrays 509 are activated during scanning of the curved region of
the bound book, i.e., upon detection of the curved region of the
bound book. One such arrangement of the light source 506 having the
outer arrays 507 and the inner arrays is shown in FIG. 9. According
to FIG. 9, two rows (507-1 and 507-2) of the outer arrays 507 are
shown. Similarly, two rows (509-1 and 509-2) of the inner arrays
509 are shown, where one array (509-1) is arranged on side of the
CIS 508, while the second array (509-2) is arranged on other side
of the CIS 508. The same arrangement is for the outer arrays 507.
As shown, the outer arrays 507 include multiple light emitting
diodes. For example, the outer array 507-1 includes light emitting
diodes as 507-1-1, 507-1-2, 507-1-3, 507-1-4 and so on. The outer
array 507-2 includes multiple light emitting diodes as 507-2-1,
507-2-2, 507-2-3, 507-2-4, and so on. Similarly, the inner arrays
509 include multiple light emitting devices. For example, the inner
array 509-1 includes light emitting diodes as 509-1-1, 509-1-2,
509-1-3, 509-1-4, and so on. The inner array 509-2 includes
multiple light emitting diodes as 509-2-1, 509-2-2, 509-2-3,
509-2-4, and so on. The light emitting diodes in the outer arrays
507 may be arranged individually or may be arranged in the form of
one or more groups. Similarly, the light emitting diodes in the
inner arrays 509 may be arranged individually or may be arranged in
the form of one or more groups. In the latter case, four light
emitting diodes may be clubbed together to form a group and many
such groups can be formed based on the number of light emitting
diodes in each inner array 509. There can be any number of light
emitting diodes in the outer arrays 507. The number of light
emitting diodes may vary in each array 507-1 and 507-2. On the
similar lines, there can be any number of light emitting diodes in
the inner arrays 509 and the number may vary in each array 509-1
and 509-2. The outer arrays 507 and inner arrays 509 may not
represent continuous arrays. The light emitting diodes in the outer
arrays 507 and/or the inner arrays 509 are capable of being
activated or deactivated individually or as one or more groups.
With the outer and inner arrays 507 and 509, the light emitting can
be changed in x direction and y direction.
The controlling processor 516 varies the intensity of light, if the
distance varies. As an example, the intensity is increased by a
quantum with which distance between the bound document 412 and the
CIS 508 increases. Similarly, the intensity may be decreased by a
quantum with which distance between the bound document 412 and the
CIS 508 decreases. The controlling processor 516 controls the outer
arrays 507 and the inner arrays 509. In one example, the
controlling processor 516 controls the inner arrays 509 to vary the
intensity of light at or along the curved region such that content
present in the curved region of the bound document 412 is captured,
upon detection of the curved region. Increasing the intensity of
light increases the reach of light in the curved region of the
bound document 412. The controlling processor 516 increases the
intensity of light by activating light emitting diodes in the inner
arrays 509. In an example, the controlling processor 516 may
activate individual inner light emitting diodes or one or more
groups of the inner light emitting diodes. The controlling
processor 516 deactivates the one activated inner light emitting
diodes when an end of the curved region is detected. In this
manner, the controlling processor 516 controls the intensity
(increase or decrease) of light based on the distance by activating
or deactivating the inner light emitting diodes at or along the
curved region "C."
The distance sensor 514 may be one of an inductive a proximity
sensor, a capacitive proximity sensor, and a photoelectric sensor.
The distance sensor 514 includes a sender 514-S to emit signals and
a receiver 514-R to receive reflected signals from the bound
document 412. Based on the time gap of receipt of the reflected
signals, the distance sensor 514 detects the distance from the
bound document 412. The scanner 300 can have multiple distance
sensors for different areas along the curved region "C" and adjust
the lighting in different portions of the curved region
separately.
In operation, a user places the bound document 412 on the platen
502 for copying or scanning. The user places the bound document 412
on the upper surface of the platen 502 for scanning. The user can
place the bound document 412 in any direction or position. For
example, the user can place the bound document 412 in landscape
orientation. In another example, the user can place the bound
document 412 in a portrait orientation, i.e., 90 degree to the
platen 502.
Upon receiving the bound document 412, the controlling processor
516 triggers the scan head 504 and the distance sensor 514. The
scan head 504 moves across in proximity to the lower surface of the
platen 502 to scan the bound document 412 placed on the upper
surface of the platen 502. While initiating scanning, the outer
arrays 507-1 and 507-2 are activated. Here, each light emitting
diode of the arrays 507-1 and 507-2 is activated and remain active
till the entire scanning operation. Upon activation, the arrays 507
emit light to illuminate the bound document 412 with an intensity,
say A. As the scan head 504 travels in the forward direction, the
distance sensor 514 continuously monitors and measures the distance
between bound document 412 and the CIS 508. The distance is
measured to detect the curved region of the bound document 412.
Initially, the distance between the bound document 412 and the CIS
508 remains constant due to the flat region and after the flat
region ends, the distance between the bound document 412 and the
CIS 508 starts increasing. The increase in the distance indicates
the curved region of the bound document 412. When the scan head 504
further travels, the distance between the bound document 412 and
the CIS 508 starts decreasing and this indicates the end of the
curved region of the bound document 412. After this, the distance
between the bound document 412 and the CIS 508 remains constant;
this indicates the flat region of the bound document 412. In this
way, the distance sensor 514 detects the curved region of the bound
document 412 and an end to the curved region "C."
Based on the distance measured, the curved region is detected. Upon
detection of the curved region, the distance sensor 514 sends a
signal to the controlling processor 516 indicating the curved
region. The controlling processors 516 generates a control command
to vary the intensity of the light to be emitted from the light
source 506 upon detection of the curved region of the bound
document 412 in order to capture a complete image of the bound
document 412 at the curved region. Based on increase in the
distance, the intensity of the light from the light source 506 is
increased by the controlling processor 304. To increase the
intensity of light, the controlling processor 516 activates the
inner arrays 509 in addition to the already activated outer arrays
507. The controlling processor 516 may activate individual multiple
light emitting diodes of the inner arrays 509. The controlling
processor 516 may activate one or more groups of the inner arrays
509 such as group 1, group 2 and so on. Each group may include four
LEDs or more. In further example, the controlling processor 516 may
activate the entire inner arrays 509. This increase in light
intensity precisely offsets the loss of reflected light by the
curved region "C" (or by the curvature of the spine region "S").
The increase in intensity of light helps enough light to reach the
curved region of the bound document 412 in order to capture the
complete image of the bound document 412. In this way, enough light
reaches the curved region of the bound document 412 that is then
captured by the CIS 508. As the curved region starts to end, the
controlling processor 516 further controls the intensity by
decreasing the intensity of light. To this end, the controlling
processor 516, deactivates the activated light emitting diodes of
the inner arrays 509. For example, the controlling processor 516
may deactivate the entire inner arrays 509, if activated. In
another example, the controlling processor 516 may deactivate the
individually activated light emitting diodes. In further example,
the controlling processor 516 may deactivate the one or more
groups, if activated. In all, the controlling processor 516
increases the illumination intensity when the distance between the
bound document 412 and the CIS 508 starts increasing in the curved
region, and then gradually decrease the illumination intensity at
the end of the curved region. It can be considered that the inner
light emitting diodes emit light of intensity B at the curved
region. At the curved region, the total intensity is A (of outer
arrays)+B (of inner arrays) and this refers to the increase in
intensity, while non-curved region is illuminated with intensity
A.
If the curved region of the bound document 412 is not parallel to
the platen 502, i.e. if one end of bound document 412 is closer to
the platen 502 than the other end, then the inner light emitting
diodes are activated based on which end of the bound document 412
is closer to the platen 502 surface. This helps in achieving even
brightness along the curved region "C."
If the curved region of the bound document 412 is uneven or if the
bound document 412 is closer to the scanner 300 at one end of the
curved region than the other end, then more number of inner light
emitting diodes at that end, where the book curved region is closer
to the scanner 300, are activated. If the curved region is closer
to the platen 502 at one end than the other end, then the inner
light emitting diodes may be clubbed into small groups.
Then, the CIS 508 starts gathering an input image from the
reflected light by the bound document 412 and sends it to the image
processor 510 for conversion to the digital form. The image
processor 510 receives the captured input image of the bound
document 412 from the CIS 508 and creates a digital version of the
bound document 412, i.e., a digital copy of the bound document 412.
While creating the digital version, the image processor 510
increases the brightness and contrast of the captured image at the
location of the curved region digitally. Finally, a digital bound
book (i.e., scanned bound book) is generated from the bound
document 412.
Thus, with the implementation of the inner arrays 509, in addition
to the outer arrays 507, the distance sensor 514 and the
controlling processor 516, the scanner 300 is able to facilitate
the CIS 508 with enough light reflected from the surface of the
bound document 412, specifically near or at the curved region of
the bound document 412. As a result, a copy of the bound document
412 is created without a dark black strip at the curved region or
without any distortion.
The memory 802 stores scanned output, stores scanning properties or
any details relevant for implementing the present disclosure.
In addition, the scanner 300 may include one or more processor(s)
(although not shown in FIG. 8). The one or more processor(s) may be
implemented as one or more microprocessors, microcomputers,
microcontrollers, digital signal processors, central processing
units, logic circuitries, and/or any devices that manipulate data
based on operational instructions. Among other capabilities, the
one or more processor(s) is configured to fetch and execute
computer-readable instructions stored in a memory 802 of the
scanner 300. The memory 802 may store one or more computer-readable
instructions or routines, which may be fetched and executed to
generate a digital document. The memory 802 may include any
non-transitory storage device including, for example, volatile
memory such as RAM, or non-volatile memory such as EPROM, flash
memory, and the like.
The scanner 300 may also include an interface(s). The interface(s)
may include a variety of interfaces, for example, interfaces for
data input and output devices referred to as I/O devices, storage
devices, and the like. The interface(s) may facilitate
communication of the scanner 300 with various devices coupled to
the scanner 300. The interface(s) may also provide a communication
pathway for one or more components of the scanner 300. Examples of
such components include, but are not limited to, the distance
sensor 514, the light source 506, the controlling processor 516,
and processing engine(s).
The processing engine(s) may be implemented as a combination of
hardware and programming (e.g., programmable instructions) to
implement one or more functionalities of the processing engine(s).
In examples described herein, such combinations of hardware and
programming may be implemented in several different ways. For
example, the programming for the processing engine(s) may be
processor executable instructions stored on a non-transitory
machine-readable storage medium and the hardware for the processing
engine(s) may include a processing resource (e.g., one or more
processors), to execute such instructions. In the present examples,
the machine-readable storage medium may store instructions that,
when executed by the processing resource, implement the processing
engine(s). In such examples, the scanner 300 may include the
machine-readable storage medium storing the instructions and the
processing resource to execute the instructions, or the
machine-readable storage medium may be separate but accessible to
scanner 300 and the processing resource. In other examples, the
processing engine(s) may be implemented by electronic
circuitry.
In one example, the processing engine(s) may include the
controlling processor 516 and the image processor 510. In an
example, the controlling processor 516 and the image processor 510
may be implemented as one or more microprocessors, microcomputers,
microcontrollers, digital signal processors, central processing
units, state machines, logic circuitries, configurable hardware
units, and/or any devices that manipulate signals based on
operational instructions.
FIG. 9 is a top view 900 of the platen 502 including CIS 508 and
the light source 506 having outer arrays 507 and inner arrays 509
arranged on both sides of the CIS 508. 507-1 and 507-2 represent
the outer arrays that remain active throughout the scanning
operation. The outer arrays 507 further include a plurality of
light emitting diodes 507-1-1, 507-1-2, 507-1-3, 507-1-4, 507-2-1,
507-2-2, 507-2-3, 507-2-4 and so on. 509-1 and 509-2 represent the
inner arrays that are activated when the curved region is detected.
The inners arrays 509 further include a plurality of light emitting
diodes 509-1-1, 509-1-2, 509-1-3, 509-1-4, 509-2-1, 509-2-2,
509-2-3, 509-2-4 and so on. The light emitting diodes in the inner
arrays 509 are selectively activated by the controlling processor
516 based on the curved region. In some examples, multiple groups
are activated, while in other examples, individuals light emitting
diodes are activated. If the curvature of the book is uneven or if
the book is closer to the scanner at one end of the curved region
than the other end, then more numbers of light emitting diodes at
that end where the book curved region is closer to the scanner 300,
are activated.
FIG. 10 shows a front view 1000 of the scanner 300. The front view
shows the platen 502, the bound book 512, and CIS 508 and the image
processor 510. When seen along the axis A-A, view (marked as 1100)
as shown in FIG. 11 is obtained. The arrow shows the curved region
of the bound book. The section A-A view further shows the outer
arrays 507 and the inner arrays 509, the inner arrays 509 are
active only during scanning of the curved region. Various groups
such as a, b, c, d, e are shown. Each group include a pre-defined
number of light emitting diodes, such as four. For example, all
groups a, b, c, d, e includes four light emitting diodes. But each
group may include any number of light emitting diodes. For example,
one group may include four light emitting diodes, another group may
include three light emitting diodes, or five light emitting diodes,
and so on. If the curved region is closer to the platen 502 at one
end than the other as shown, then the light emitting diodes are
clubbed into small groups and activated.
Method Flowcharts
FIG. 12 is a method flowchart 1200 for scanning a bound document
such as a bound book. Reference to other figures may be made while
discussing FIG. 12. Specifically, the method flowchart 1200 relates
to scanning a bound document with varying light intensity. The
method is implemented by a scanner 300, which uses light sources
whose output intensity can be varied with the help of additional
light sources such as light emitting diodes. The order in which the
method 1200 is described is not intended to be construed as a
limitation, and any number of the described method blocks can be
combined in any appropriate order to carry out the method or an
alternative method.
The method 1200 can be performed by programmed computing devices,
for example, based on instructions retrieved from the
non-transitory computer-readable medium or non-transitory
computer-readable media. The computer-readable media can include
machine-executable or computer-executable instructions to perform
all or portions of the described method. The computer-readable
media may be, for example, digital memories, magnetic storage
media, such as magnetic disks and magnetic tapes, hard drives, or
optically readable data storage media.
During scanning of a bound book, issues such as dark images/strips
in a curved region or content missing are faced due to lack of
reachability of light in the curved region. To overcome such issue,
the method 1200 introduces a feature of increasing intensity of
light to increase the reachability of light to the curved region in
order to capture the complete content present therein. To this end,
the method 1200 first identifies the curved region based on the
distance between the bound document and a contact image sensor
(CIS). The bound document is flat but is curved in the center
region. Accordingly, those skilled in the art can appreciate that
the constant distance between the bound document and the CIS
defines the flat region, while the varying distance between the
bound document and the CIS unit defines the curved/spine/binding
region.
The method 1200 begins when a user wishes to create a digital
version of the bound book. The digital version is created by
scanning or copying the bound document. The user submits the bound
book for scanning. At block 1202, the bound document 412 is
received that is positioned on an upper surface of a platen 502 of
the scanner 300. The bound book, when opened for scanning, includes
a flat region and a curved region. The scanning is performed by a
movable scan head 504 of the scanner 300. The light sources include
a plurality of light emitting diodes whose output intensity is
adapted to be varied with the use of additional light emitting
diodes.
At block 1204, the distance between the bound book positioned on
the platen and a contact image sensor (CIS) unit 508 is
continuously monitored and measured. The distance between a lower
face of the bound book positioned on the platen 502 of the scanner
300 and the contact image sensor (CIS) is continuously monitored
and measured. The distance measurement starts when the scan head
504 starts moving from left to right in the x-axis direction. The
distance is measured to detect the curved region of the bound book.
When the distance between the bound book and the CIS remains
constant, the region is defined as the flat region of the bound
book. When the distance between the bound book and the CIS is
varied, the region is defined as the curved region of the bound
book 512. In this way, the curved region of the bound book is
detected. In an example, when the measured distance is within a
specified range then, the light is emitted with a pre-defined
intensity. When the measured distance is above the specified range,
the light is emitted with an increased intensity in the bound
document's curved region. The value of the increased intensity is
directly proportional to the quantum of increase in the measured
distance above the specified range.
At 1206, a control command is generated to vary the intensity of
light to be emitted from the light source, upon detection of the
curved region. The intensity of light is varied such that content
present in the curved region of the bound document is captured. At
1208, based on the control command, the light with varying
intensity is emitted for illuminating the curved region of the
bound book. Emitting the light with varying intensity includes
emitting the light with increased illumination intensity when the
distance between the bound document and the CIS starts increasing
in the curved region. Emitting the light with varying intensity
further includes gradually decreasing the illumination intensity of
the emitted light at the end of the curved region. As a result, the
light source emits light on the platen with increased intensity in
order to increase the reach through the curved region of the bound
book or to reach the depth of the curved region of the bound book.
Emitting light with increased intensity, by the light source, on
the platen in the detected curved region of the bound document
increases the reach through the curved region of the bound
document.
The light emitted on the bound book is reflected from the bound
book. The light with increased intensity gets reflected by the
bound book, which is then captured by the CIS to capture
images.
At 1210, the light reflected from the bound book is received for
capturing an image of the bound book. Using the reflected light,
the CIS captures images of the curved region accurately and
completely. In this manner, images of the curved region are
captured. Finally, at 1212, a digital version of the bound book is
generated.
FIG. 13 is a method flowchart 1300 for scanning a bound document.
Reference to other figures may be made while discussing FIG. 13.
The method 1300 is implemented at a scanner such as 300 or a
photocopier device. The scanner 300 includes a light source such as
light emitting devices. One such example of light emitting devices
is light emitting diodes without limiting the scope of disclosure.
The light source includes outer arrays of light emitting diodes and
inner arrays of light emitting diodes, arranged on both sides of a
contact image sensors such as 508.
The method 1300 begins when a user wishes to scan a bound document.
The user submits the bound document to the scanner 300. In
particular, the user positions the bound document on a platen such
as 502 of the scanner 300. At 1302, the bound document is received
on the platen of the scanner 300. The bound document has a flat
region and a curved region. Upon receiving the bound document,
scanning of the bound document is initiated. While initiating
scanning, the outer arrays of light emitting diodes are activated
and remain activated during the entire scanning operation. Here,
each outer light emitting device is activated to illuminate the
bound document. The outer arrays of light emitting diodes emit
light of given intensity.
At 1304, while scanning, a distance between the bound document and
the contact image sensor is continuously monitored and measured in
order to detect the curved region. For example, if the distance
remains constant, the region defines the flat region of the bound
document. If the distance starts varying between the bound document
and the contact image sensor because of the curved region (i.e.,
curvature of the paper), then the curved region is defined. At
1306, upon detection of the curved region, a control command is
generated to increase the intensity of the light source at or along
the curved region.
The distance measurement is used to adjust the light intensity so
that when the bound document 412 is further from the contact image
sensor 508 (such as near the curved region of the book), the light
is increased to prevent the creation of a dark band in the scanned
image.
In an implementation, the brightness output may be controlled by
activating and deactivating a desired number of the inner light
emitting diodes, while all outer light emitting diodes remain
active throughout the scanning operation.
At 1308, the inner arrays of the light emitting diodes are
activated to increase the intensity of light in the curved region
of the bound document, in addition to the already activated outer
arrays. The inner arrays are activated only when the curved region
is detected. The inner arrays include a plurality of light emitting
diodes. In an example, each light emitting diode of the inner
arrays are activated. In another example, some individual light
emitting diodes are activated. In further example, one or more
groups of light emitting diodes are activated. The inner arrays of
the light emitting diodes when activated increases the intensity of
light. The inner arrays emit light to illuminate the curved region
such that content present in the curved region is well
captured.
Then, the distance is continuously monitored and measured to detect
the end of the curved region. When the distance between the bound
document the contact image sensor decreases, the end of the curved
region is detected. Upon detection of the end of the curved region,
the inner arrays of the light emitting diodes are deactivated. For
example, if each light emitting diodes of the inner arrays is
activated then, each activated light emitting diodes is
deactivated. In another example, if one or more groups are
activated, then the activated one or more groups are deactivated.
In this way, scanning of the bound document is finished.
The outer arrays of light emitting diodes emit light of defined
intensity and with the use of additional light source such as inner
arrays of light emitting diodes, the intensity of the light source
is varied (increase and decrease). The intensity of light is
increased by activation of the inner arrays and the intensity of
light is decreased by deactivation of the inner arrays.
In an example, the brightness output is controlled by activating
and deactivating a desired number of the inner light emitting
diodes.
If the curved region of the bound document is not parallel to the
platen, i.e. if one end of bound document is closer to the platen
than the other end, then a desired number of inner light emitting
diodes are activated based on which end of the book is closer to
the platen surface. This helps in achieving even brightness along
the curved region.
The light emitted on the bound document is reflected by the bound
document. At 1310, the light reflected from the bound document is
gathered to capture a complete image of the bound document.
Finally, a digital version of the bound document is generated based
on the captured image.
Thus, with the implementation of the scanner of the present
disclosure, the digital document as generated without having any
dark image reproduction in the curved region or without any
distortion.
The present disclosure discloses methods and systems for scanning
bound document with varying light intensity. The bound documents
are scanned such that there is no black strip at the center while
scanning the bound documents because of the curvature of the paper
in the center. Also, there is no distortion in the scanned bound
documents. Varying the light intensity helps avoid the problem of
reachability of light in the curved region, thereby no content is
missed. Further, varying the intensity of light helps enough light
to reach to the contact image sensors in order to capture the
complete image of the bound document. In addition, the user does
not require to push the bound documents hard on to a platen to
decrease the gap between a sensor and the paper.
The order in which the method is described is not intended to be
construed as a limitation, and any number of the described method
blocks can be combined in any order to implement the method or
alternate methods. Additionally, individual blocks may be deleted
from the method without departing from the spirit and scope of the
subject matter described herein. Furthermore, the method can be
implemented in any suitable hardware, software, firmware, or
combination thereof. However, for ease of explanation, in the
embodiments described below, the method may be considered to be
implemented in the above-described system and/or the apparatus
and/or any electronic device (not shown).
The above description does not provide specific details of
manufacture or design of the various components. Those of skill in
the art are familiar with such details, and unless departures from
those techniques are set out, techniques, known, related art or
later developed designs and materials should be employed. Those in
the art are capable of choosing suitable manufacturing and design
details.
Note that throughout the following discussion, numerous references
may be made regarding servers, services, engines, modules,
interfaces, portals, platforms, or other systems formed from
computing devices. It should be appreciated that the use of such
terms is deemed to represent one or more computing devices having
at least one processor configured to or programmed to execute
software instructions stored on a computer readable tangible,
non-transitory medium or also referred to as a processor-readable
medium. For example, a server can include one or more computers
operating as a web server, database server, or other type of
computer server in a manner to fulfill described roles,
responsibilities, or functions. Within the context of this
document, the disclosed devices or systems are also deemed to
comprise computing devices having a processor and a non-transitory
memory storing instructions executable by the processor that cause
the device to control, manage, or otherwise manipulate the features
of the devices or systems.
Some portions of the detailed description herein are presented in
terms of algorithms and symbolic representations of operations on
data bits performed by conventional computer components, including
a central processing unit (CPU), memory storage devices for the
CPU, and connected display devices. These algorithmic descriptions
and representations are the means used by those skilled in the data
processing arts to most effectively convey the substance of their
work to others skilled in the art. An algorithm is generally
perceived as a self-consistent sequence of steps leading to a
desired result. The steps are those requiring physical
manipulations of physical quantities. Usually, though not
necessarily, these quantities take the form of electrical or
magnetic signals capable of being stored, transferred, combined,
compared, and otherwise manipulated. It has proven convenient at
times, principally for reasons of common usage, to refer to these
signals as bits, values, elements, symbols, characters, terms,
numbers, or the like.
It should be understood, however, that all of these and similar
terms are to be associated with the appropriate physical quantities
and are merely convenient labels applied to these quantities.
Unless specifically stated otherwise, as apparent from the
discussion herein, it is appreciated that throughout the
description, discussions utilizing terms such as receiving,
monitoring, measuring, scanning, controlling, adjusting, or the
like, refer to the action and processes of a computer system, or
similar electronic computing device, that manipulates and
transforms data represented as physical (electronic) quantities
within the computer system's registers and memories into other data
similarly represented as physical quantities within the computer
system memories or registers or other such information storage,
transmission or display devices.
The exemplary embodiment also relates to an apparatus for
performing the operations discussed herein. This apparatus may be
specially constructed for the required purposes, or it may comprise
a general-purpose computer selectively activated or reconfigured by
a computer program stored in the computer. Such a computer program
may be stored in a computer readable storage medium, such as, but
is not limited to, any type of disk including floppy disks, optical
disks, CD-ROMs, and magnetic-optical disks, read-only memories
(ROMs), random access memories (RAMs), EPROMs, EEPROMs, magnetic or
optical cards, or any type of media suitable for storing electronic
instructions, and each coupled to a computer system bus.
The algorithms and displays presented herein are not inherently
related to any particular computer or other apparatus. Various
general-purpose systems may be used with programs in accordance
with the teachings herein, or it may prove convenient to construct
more specialized apparatus to perform the methods described herein.
The structure for a variety of these systems is apparent from the
description above. In addition, the exemplary embodiment is not
described with reference to any particular programming language. It
will be appreciated that a variety of programming languages may be
used to implement the teachings of the exemplary embodiment as
described herein.
The methods illustrated throughout the specification, may be
implemented in a computer program product that may be executed on a
computer. The computer program product may comprise a
non-transitory computer-readable recording medium on which a
control program is recorded, such as a disk, hard drive, or the
like. Common forms of non-transitory computer-readable media
include, for example, floppy disks, flexible disks, hard disks,
magnetic tape, or any other magnetic storage medium, CD-ROM, DVD,
or any other optical medium, a RAM, a PROM, an EPROM, a
FLASH-EPROM, or other memory chip or cartridge, or any other
tangible medium from which a computer can read and use.
Alternatively, the method may be implemented in a transitory media,
such as a transmittable carrier wave in which the control program
is embodied as a data signal using transmission media, such as
acoustic or light waves, such as those generated during radio wave
and infrared data communications, and the like.
The terminology used herein is for the purpose of describing
particular embodiments only and is not intended to be limiting of
the disclosure. It will be appreciated that several of the above
disclosed and other features and functions, or alternatives
thereof, may be combined into other systems or applications.
Various presently unforeseen or unanticipated alternatives,
modifications, variations, or improvements therein may subsequently
be made by those skilled in the art without departing from the
scope of the present disclosure as encompassed by the following
claims.
The claims, as originally presented and as they may be amended,
encompass variations, alternatives, modifications, improvements,
equivalents, and substantial equivalents of the embodiments and
teachings disclosed herein, including those that are presently
unforeseen or unappreciated, and that, for example, may arise from
applicants/patentees and others.
It will be appreciated that variants of the above-disclosed and
other features and functions, or alternatives thereof, may be
combined into many other different systems or applications. Various
presently unforeseen or unanticipated alternatives, modifications,
variations, or improvements therein may be subsequently made by
those skilled in the art which are also intended to be encompassed
by the following claims.
* * * * *